Pencil sharpener hone



July 30, 1935.

F. J. KERCHEVAL PENCIL SHARRENER HONE Filed 001;. 31, 1934 2 Sheets-Sheet 2 In venton Fre' JIereke a Patented July 30, 1935 UNI-TED STATES PATENT OFFICE PENCIL SHARPENER HONE Fred J. Kercheval, Rowan, Iowa Application October 31, 1934, Serial No. 750,827

' 9 Claims. (01. 51 154) This invention relates to a hone for sharpening rotary cutters, such for example, as pencil sharpener cutters, cylindrical or conical reamers and the like cutting tools having a plurality of knives or blades extending longitudinally of v or spirally about a cylindrical orconical shaped body portion.

The principal object of the invention is to provide a. hone or sharpener for accurately grinding'rotary cutters so that their cutting surfaces are symmetrically ground to the proper degree of curvature.

Another object is .to provide an apparatus which is of simple design having but few parts,

which is of strong and durable construction,

which is economical to manufacture and eflicient and reliable in operation.

Further objects relate to the. operation and to features of construction of my new apparatus and will be apparent from a consideration of the following description and accompanying drawings wherein: v

Fig. 1 is a top plan view of my new; apparatus;

Fig. 2 is a side elevation of the apparatus shown in Fig. 1;

Fig. 3 is a front elevation of the apparatus with a portion of the belt broken away;

Fig. 4 is an enlargedend elevation of the-abrasive belt and sharpener; and

Fig. 5 is a side elevation of a modified form of apparatus. a

The embodiment shown in Figs. 1 to 3 comprises a base or stand I having a centrally disposed upright 2 which supports an elongated bearing 3. The base I is provided with suitable openings-on each side of the upright for the reception of screws 4 and 5 by means of which the apparatus may be firmly secured to the top of a table, bench, or other suitable support.

A spindle 8 is journaled in the bearing 3 and projects outwardly beyond the ends of the bearing, one end of the spindle being integral with a crank 9 provided with a handle ID by means of which the spindle may be rotated manually. The other end of the spindle carries a clutch member, chuck or other suitable means for holding a rotary cutter such as a pencil sharpener cutter l2 having the usual gear or cog l4 rigidly secured to one .end. As here shown the, clutching member comprises a cylindrical sleeve or collar l5 which carries a set screw l6 adjacent to'one end and a stub shaft I! having a pressed fit within the bore of its opposite end and projecting outwardly, as shownin Figs. 1 and 3. The collar I5 is rigidly secured to the spindle '8 by the set screw It so that its inner end abuts the adjacent end of the bearing 3. When thus assembled, the stub shaft IT is held in axial alignment with the spindle B and, in effect, constitutes a part thereof. A clutching member or resilient latch finger l8, in tegrally joined in any suitable manner to' the collar [5, projects outwardly so as to engage the cog l4 betweenany two of its teeth, thereby tohold the pencil sharpener cutter l2 firmly in place on the stub shaft ll. 7 a

In order to prevent axial movementiof the spindle and shaft, the end of the spindle intermediate the bearing 3 and crank 9 may be'provided with a thrust washer 20 and a-pin 2| which passes through the spindle and holds the washer 20 against the adjacent end of the bearing 3. The collar [5 abutting one end of the bearing 3 prevents axial movement of the spindle toward the right (Figs. 1 and 3) and in like manner the. washer 20 prevents axial movement of the spine dle toward the left.

An extension bar 25 having a bifurcated end 26 is mounted on the base I with its upwardly bent free end 21 projecting outwardly beyond the end of the base. and a clamping screw 29 which passes through the slot of the bifurcated end 26, the position of the extension bar 25 relative to both the base I and stub shaft I1 may be adjusted as desired. A belt holder 30 is pivotally mounted on the free end 2'! of the extension bar so as to swing toward and away from the stub shaft lland, as here shown, preferably consists of a length of heavy steel wire or the like bent to provide a handle portion 32 which projects outwardly substantially at right angles from the extension bar and an end portion 3 constituting the belt holder, proper, which extends substantially horizontally. The periphery of the holder proper is preferably burred or otherwise roughened so as to provide a row of teeth 34, as shown more clearly in Fig. 4.

length of the cutter l2. The abrasive belt is held in yielding engagement with a longitudinal segmental portion of the cutter l2 by means .Of a coil tension spring 38 (Fig. 2), one end of which is anchored to the end 21 of the extension bar and the other end-to the handle portion 32 of By meansof a washer 28.

the belt holder. The spring 38 is normally under sufiicient tension to urge the handle downwardly against the support upon which the base rests and is operative to exert suificient tension on the belt to keep it taut and cause the teeth 34 to bite into the belt so as to hold it stationary when the cutter is rotated.

In using my apparatus the cutter to be sharpened is first mounted on the stub shaft ll so that the clutch finger I8 engages the cog l4. The extension bar 25 may then be adjusted to correspond with the position of the c utter ['2 (if such has not already been done). Where the cutter to be sharpened is cylindrical inshape, as here shown, the holder 33 is positioned so that it is substantially parallel to the axis of rotation of the shaft I1; but if the cutter to be sharpened is conical in shape, then the extension barzshould be positioned so that the holder 33 is at an angle to the axis of the shaft ll. After properly'positioning the holder the belt is :then applied and the apparatus is operated by turning the crank handle so as to rotate the cutter in the direction shown by the arrow in Fig. 4 the operation being continued until the desired cutting edge is produced. If desired, additional force may be applied to the cutter during the grinding operation bygrasping the handle32 and bearing down slightly, thus assisting the action of the spring 38.

By reason of the flexibility of'the belt 35 and the action of the spring 38, the contacting abra- Sive surface of the :belt conforms precisely with the-curvature of the cutter and isat all times held coaxial with both the cutter, and shaft. By properly adjusting the holder :33 the tension on the belt is-uniformly distributed so that the cutting edges or surfaces of the cutter 12 are subjected to a uniform grinding pressure and hence are symmetrically ground 'to the proper curvature. Be-

tween grinding operations a fresh abrasive surface may be presented merely by releasing the tension on the belt so as to permit it-to :be moved in either direction.

In Fig. 5 I have shown a modification wherein an electric motor is used to rotate the cutter. In this embodiment the electric motor 45 .is secured in any suitable manner to a support such as the top of a .benchor table and the extension bar 25 may be adjustably secured to the same support in any suitable manner, as, for example, by clamping screws .29. The collar 15 is rigidly secured to the projecting end of the motor shaft 45 by the set screw I6 and supports the stub shaft .l] on which the cutter I2 is mounted as in the previously described embodiment. The remaining parts of the apparatus are similar to those above described and the same reference characters have been applied thereto. The operation is substantially the same as that previously described, except that the motor is used to rotate the cutter instead of a manually operated crank handle.

While I have shown and described different desirable embodiments of the present invention, it is to be understood that this disclosure is for the purpose of illustration only and that various changes in shape,-proportion and arrangement of parts, as well as the substitution of equivalent elements for those herein shown and described, may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. A phone for a'pencil sharpener or the like cuttingtooL'comprising means for supporting a rotary cutter for rotation about a fixed axis, means for supporting a flexible belt of abrasive material in a position to engage a longitudinal segment of the cutter. and means for rotatin said cutter.

2. A hone for a pencil sharpener or the like cutting tool, comprising means for supporting a rotary cutter for rotation about a fixed axis, means for supporting a flexible belt in yielding engagement with said cutter, and means for rotating said cutter. r

3. A hone for a pencil sharpener or the like cutting tool, comprising means for supporting a circum-posedabout a portion of the cutter, means operative yieldingly to hold said belt in engagement was a longitudinal segment of said cutter, and means for rotating said cutter.

4; A hone for a pencil sharpener or the like cutting tool, comprising means for supporting a rotary cutter .for rotation about a fixed axisp'a holding member ofiset relative to the axis 'of rotation of said cutter, a flexible belt of abrasive materialcircumposed about said holding member and adapted to fit about said cutter so as to contact a longitudinal segmental portion of its periphery, and means for rotating 'said -cutter.

5. A hone for a pencil sharpener 'or the like cutting tool, comprising means :for supporting a. rotary cutter for rotation about a fixed axis, a holdingmember offset relative to the axis oi. rotation of said cutter, a flexible belt of abrasive material circumposed about said holdingmember and adapted to fit about said cutter so as to contact a longitudinal segmental portion of its periphery, resilient means for tensioning said belt, and-means for rotating said cutter.

'6. A hone for a pencil sharpener or the like cutting tool, comprising a spindle having clutching means for holding a rotary cutter'for rotation about a fixed axis, a holding member ofi'set relative to and movable toward and away from said spindle, a flexible belt of abrasive material adapted to fit about said rotary cutter and said holding member so as to contact a longitudinal segmental portion of said cutter, resilient means urging said holding 'member away from said spindle, thereby to tension said belt and-hold it in fixed position, and means for rotating said spindle.

'7. A hone for a pencil sharpener or the like cutting tool, comprising a spindle having clutching means for holding a rotary cutter for rotation about a fixed axis, a holding member oil"- set relative to and pivotally mounted to swing toward and away from said spindle, a flexible belt of abrasive material adapted to fit about said rotary cutter and said holding member so as to contact a longitudinal segmental portion of said cutter, a spring acting on said holding memberand operative to tension said belt and hold it in fixed .position, and means for rotating'said spindle.

8. A hone for apencil sharpener or the like cutting tool, comprising a spindle having clutching means for holding a rotary cutter for rotafor tensioning said loop of abrasive material, and means for rotating said spindle.

9. A hone for a pencil sharpener or the like cutting tool, comprising a spindle having clutching means for holding a rotary cutter for rotation about a fixed axis, a holding member offset relative to and mounted to move toward and away from said spindle, a flexible loop of abrasive material anchored to said holding member and adapted to fit about said rotary cutter so .as to contact a longitudinal segmental portion of its periphery, resilient means urging said holding member away from said spindle and operative to tension said 1001) and hold it in fixed position, and means for rotating said spindle.

FRED J. KERCHEVAL. 

